1. Diodes Properties of SWNT Networks Bryan Hicks

2. Diodes and Transistors An ever increasing number in an ever decreasing area

3. Why Carbon Nanotubes? Ballistic transport –Low power No chemical passivation necessary allows for a variety of different insulators Current densities of 10 9 A/cm 2 vs. 10 3 A/cm 2 for silicon Huge mobility for high speed devices Can be semi-conducting or metallic

4. Carbon Nanotube Networks Random networks of tubes Low resistance at CNT junctions No processing necessary 1/3 metallic 2/3 semiconducting Have properties of both metals and semiconductors

5. Fabrication Process Deposit Al and Au electrodes on to a Si0 2 /Si chip with SWNT networks Wire bond the electrodes to a chip carrier

6. Actual Devices

7. Current Rectification Properties Maximum Current Capacities: Device 1: 8 μA & Device 2: 22 μA On/off ratios: Device 1: 20 & Device 2: 5

8. Current Rectification Properties Maximum Current Capacities: 678.9 μA On/off ratios: 27

9. Current Rectification Properties Maximum Current Capacities: 840 μA On/off ratios: 108

10. Current Rectification Properties Maximum Current Capacities: 840 μA On/off ratios: ??

11. Gate Voltage Characterization Current decreases as carriers are removed Current increases as carriers are introduced The hysteresis seen is due to trapping seen in other CNT transistors as well

12. Summary Carbon Nanotube Networks present an economic way to incorporate CNT properties into macroelectronics Current Rectification seems to be a product of contact resistance and is often lost when various scans are made.

13. Sources C. Lu, L. An, Q. Fu, J. Liua, H. Zhang and J. Murduck. Appl. Phys. Lett. 88, 133501 (2006) P. Avouris, J. Appenzeller, Richard Martel, And S. J. Wind. Proceedings of the IEEE. 91, 11 (2003)